Components in gas turbine engines are normally replaced when their useful lifetimes are reached. Of course, if damage occurs to a component, that component will be replaced earlier.
However, in some cases, the lifetimes of components are measured not by the structural viability of the components, but by other factors. Such components are replaced, even though they are structurally sound and could remain in service.
For example, if the acceleration of an engine falls below a target, a type of overhaul is undertaken, wherein numerous components are replaced. However, in many instances, the slowly accelerating engine is perfectly sound, and contains sound components. The engine merely suffers from slow acceleration, and the overhaul and component replacement are undertaken for that reason.
As another example, some components are replaced after they have experienced a certain amount of thermal cycling, or have been exposed to high temperatures for certain lengths of time. However, these components are not necessarily faulty.
The invention has developed an approach to increasing lifetimes of certain components in gas turbine engines.